Electronic component and component-embedded substrate

ABSTRACT

An electronic component includes: a component body into which elements are built; and a metal plate electrode that is joined to the component body by conductive paste so as to be electrically coupled to the elements, wherein the metal plate electrode exceeds in size a surface of the component body onto which the conductive paste is deposited.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2015-141196, filed on Jul. 15,2015, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to an electronic componentand a component-embedded substrate.

BACKGROUND

With miniaturization of and performance improvement in electronicequipment in recent years, use of interconnection substrates (which willbe referred to as “component-embedded substrates” hereinafter) in whichelectronic components such as capacitors and resistors are embedded hasincreased. A component-embedded substrate is manufactured by insertionof electronic components into holes made in a core substrate, fixationof the electronic components with resin, and sequential formation ofinsulating layers, vias, and interconnections, for instance. Laser isused for the formation of the vias.

As the electronic components embedded in the interconnection substrate,electronic components that are the same as chip components for surfacemounting are often used.

Conventionally, an electronic component for surface mounting in whichleads are connected through metal plates to a chip component has beenproposed. Besides, there has been proposed an electronic component to beembedded in a substrate, in which the electronic component includeselectrodes each having a structure with lamination of a foundation layerformed by baking of metallic paste containing glass and a surface layerformed by baking of metallic paste not containing glass.

Positional deviations may occur when the vias to be connected to theelectronic components embedded in the substrate are formed. In casewhere the positional deviations of the vias occur, increases inresistances between the electronic components and the vias may causemalfunction or the like.

The followings are reference documents.

[Document 1] Japanese Laid-open Patent Publication No. 2000-306764 and[Document 2] Japanese Laid-open Patent Publication No. 2014-123707.SUMMARY

According to an aspect of the invention, an electronic componentincludes: a component body into which elements are built; and a metalplate electrode that is joined to the component body by conductive pasteso as to be electrically coupled to the elements, wherein the metalplate electrode exceeds in size a surface of the component body ontowhich the conductive paste is deposited.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic sectional view illustrating an example of anelectronic component that is to be embedded in a substrate for use;

FIG. 2 is a schematic diagram of an electronic component according to anembodiment;

FIG. 3 is a top plan view of the electronic component according to theembodiment;

FIGS. 4A to 4C are diagrams illustrating steps of manufacturing theelectronic component;

FIGS. 5A and 5B are schematic sectional views (part 1) illustrating amethod of manufacturing a component-embedded substrate in which theelectronic component is used;

FIGS. 6A and 6B are schematic sectional views (part 2) illustrating themethod of manufacturing the component-embedded substrate in which theelectronic component is used;

FIGS. 7A and 7B are schematic sectional views (part 3) illustrating themethod of manufacturing the component-embedded substrate in which theelectronic component is used;

FIG. 8 is a schematic sectional view (part 4) illustrating the method ofmanufacturing the component-embedded substrate in which the electroniccomponent is used;

FIG. 9 is a top plan view illustrating effects of the electroniccomponent according to the embodiment;

FIG. 10 is a schematic sectional view illustrating an example of anelectronic component in which film thicknesses of external electrodesare increased for avoidance of breakage that may be caused by laser;

FIG. 11A is a schematic diagram illustrating an electronic componentaccording to modification 1; FIG. 11B is a schematic sectional viewillustrating a component-embedded substrate in which the electroniccomponent according to modification 1 is used;

FIG. 12A is a schematic diagram illustrating an electronic componentaccording to modification 2; FIG. 12B is a schematic sectional viewillustrating a component-embedded substrate in which the electroniccomponent according to modification 2 is used;

FIG. 13A is a schematic diagram illustrating an electronic componentaccording to modification 3; FIG. 13B is a schematic sectional viewillustrating a component-embedded substrate in which the electroniccomponent according to modification 3 is used;

FIG. 14A is a schematic diagram illustrating an electronic componentaccording to modification 4; FIG. 14B is a schematic sectional viewillustrating a component-embedded substrate in which the electroniccomponent according to modification 4 is used; and

FIG. 15 is a perspective view illustrating an example of electronicequipment that includes the component-embedded substrate.

DESCRIPTION OF EMBODIMENT

Hereinafter, description on preliminary matters for facilitatingunderstanding of an embodiment will be provided before description onthe embodiment.

FIG. 1 is a schematic sectional view illustrating an example of anelectronic component that is to be embedded in a substrate for use.Herein, the description will be given with use of a chip ceramiccapacitor as the example of the electronic component.

The electronic component 10 illustrated in FIG. 1 includes a componentbody 11 that has a structure in which a plurality of ceramic(dielectric) sheets and a plurality of internal electrodes 13 arelaminated and a pair of external electrodes 12 a, 12 b that areelectrically connected to the internal electrodes 13.

The external electrodes 12 a, 12 b are formed by deposition ofconductive paste onto upper and lower surfaces of the component body 11by dipping and subsequent heat treatment (baking treatment) at aspecified temperature. Accordingly, the external electrodes 12 a, 12 bhave a rounded shape.

Laser is used for formation of vias to be connected to the electroniccomponent 10 embedded in the substrate. Positional deviations, however,may occur between the vias and the external electrodes 12 a, 12 bbecause a certain amount of positional deviation occurs when theelectronic component 10 is placed in a hole in the substrate and becausethe electronic component 10 is covered with resin so as to be invisibleduring irradiation with the laser.

For the embodiment below, description will be given on an electroniccomponent in which reliable connection between vias and electrodes maybe provided even if the positional deviations occur in formation of thevias and on a component-embedded substrate in which the electroniccomponent is used.

Embodiment

FIG. 2 is a schematic diagram of the electronic component according tothe embodiment and FIG. 3 is a top plan view of the electronic componentaccording to the embodiment. As the embodiment, an example in which theelectronic component is a chip ceramic capacitor will be described.

As illustrated in FIG. 2, the electronic component 20 according to theembodiment includes a component body 21, baked electrodes 22, and metalplate electrodes 23 a, 23 b. The baked electrodes 22 are made ofconductive paste having undergone baking treatment.

The component body 21 has a structure in which a plurality of ceramic(dielectric) sheets and a plurality of internal electrodes 24 arelaminated and a specified capacity is provided by the internalelectrodes 24 and the ceramic. The internal electrodes 24 are an exampleof elements built in the component body 21.

The metal plate electrode 23 a is joined onto an upper part of thecomponent body 21 through the baked electrode 22. The metal plateelectrode 23 b is joined onto a lower part of the component body 21through the baked electrode 22.

For convenience of description, hereinafter, surfaces of the componentbody 21 onto which the baked electrodes 22 (conductive paste) aredeposited will be referred to as electrode joint surfaces. In theexample illustrated in FIG. 2, top and bottom surfaces of the componentbody 21 are the electrode joint surfaces.

The metal plate electrode 23 a exceeds the upper electrode joint surfaceof the component body 21 in size (area) and edge parts of the metalplate electrode 23 a protrude laterally from the component body 21. Asillustrated in FIG. 3, length and width (X1, Y1) of the component body21 as seen looking from above are 200 μm, for instance, and length andwidth (X2, Y2) of the metal plate electrode 23 a as seen looking fromabove are between 300 μm and 500 μm, for instance.

By contrast, the metal plate electrode 23 b has generally the samelength and width as the lower electrode joint surface of the componentbody 21 has.

In the electronic component 20 illustrated in FIG. 2, a recessed part isformed at center on a lower surface of the metal plate electrode 23 aand a part of the metal plate electrode 23 a that fits the componentbody 21 is thinner than the edge parts of the metal plate electrode 23a. This configuration is intended for facilitating positioning betweenthe electronic component 20 and the metal plate electrode 23 a.Provision of the recessed part on the metal plate electrode 23 a hasadvantages in that the provision allows a height of the component body21 to be increased by a depth of the recessed part and thereby makes iteasier to ensure desired characteristics (capacity value, withstandvoltage, or the like, for instance). The recessed part of the metalplate electrode 23 a is not indispensable and may be formed asappropriate.

FIGS. 4A to 4C are diagrams illustrating steps of manufacturing theelectronic component 20 described above.

Initially, conductive coating material that is to form the internalelectrodes 24 is applied with specified patterns onto surfaces of theceramic sheets (green sheets). After that, the plurality of ceramicsheets are laminated, integrated by application of a pressure, cut intopieces with a specified size, and thereafter fired by heat treatment ata temperature between 1000° C. and 1300° C., for instance. Thus thecomponent body 21 illustrated in FIG. 4A is finished.

As illustrated in FIG. 4B, the conductive paste 25 is subsequentlydeposited on the top and bottom surfaces of the component body 21 bydipping. As the conductive paste 25, metal paste of copper, silver, orthe like, resin (conductive resin) containing filler metal havingconductivity, or the like may be used, for instance.

As illustrated in FIG. 4C, the metal plate electrodes 23 a, 23 b areaffixed onto the conductive paste 25 when the conductive paste 25 is ina semi-hardened state. Copper plates, kovar plates, or the like may beused as the metal plate electrodes 23 a, 23 b. Thicknesses of the metalplate electrodes 23 a, 23 b have only to be such as to ensure protectionof the component body 21 during irradiation with laser and are between10 μm and 15 μm, for instance.

After that, the conductive paste 25 is baked by heat treatment at atemperature of 800° C., for instance, so as to be made into the bakedelectrodes 22. Thus the metal plate electrodes 23 a, 23 b are tightlyconnected to the component body 21 through the baked electrodes 22 andthe electronic component 20 illustrated in FIG. 2 is thereby finished.

FIGS. 5A to 8 are schematic sectional views illustrating a method ofmanufacturing a component-embedded substrate in which the electroniccomponent 20 described above is used, in accordance with a sequence ofsteps.

As illustrated in FIG. 5A, initially, a core substrate 31 is preparedand holes 32 piercing through the core substrate 31 are formed by adrill at specified positions on the core substrate 31. A diameter of theholes 32 is such as to permit the component body 21 and the metal plateelectrode 23 b of the electronic component 20 to enter the holes 32.

The electronic components 20 are thereafter inserted into the holes 32.In the embodiment, as illustrated in FIG. 5B, the component bodies 21and the metal plate electrodes 23 b are placed in the holes 32 and themetal plate electrodes 23 a are placed on the holes 32.

As illustrated in FIG. 6A, subsequently, the holes 32 are filled withresin 33 so that the electronic components 20 are fixed and prepreg 34is affixed onto upper and lower surfaces of the core substrate 31.

As illustrated in FIG. 6B, subsequently, resin coated copper foil (RCC)35 including copper foil 35 a and insulating films 35 b is affixed ontothe upper and lower surfaces of the core substrate 31.

After that, as illustrated in FIG. 7A, laser is used to form via holes36 at specified positions on the RCC 35 and to expose the metal plateelectrodes 23 a, 23 b.

Subsequently, desmear is carried out in the via holes 36 and copper isthereafter deposited in the via holes 36 by plating so as to form vias37 as illustrated in FIG. 7B. After that, the copper foil is subjectedto patterning by photolithography so that interconnections 38 areformed.

Subsequently, steps of affixing the RCC, forming the via holes, andforming the vias and the interconnections are iterated and acomponent-embedded substrate 40 having such a multilayer interconnectionstructure as illustrated in FIG. 8 is finished.

In the electronic component 20 according to the embodiment, the metalplate electrode 23 a is made to exceed the electrode joint surface ofthe component body 21 in size. Therefore, reliable connection betweenthe metal plate electrode 23 a and the via 37 may be provided even ifthe via 37 is formed at a position deviated from a center part of thecomponent body 21 as illustrated in a top plan view of FIG. 9, forinstance.

In the electronic component 20 according to the embodiment, asillustrated in FIG. 2, the electrode joint surfaces of the componentbody 21 are covered with the metal plate electrodes 23 a, 23 b. When theelectronic component 20 is irradiated with the laser during formation ofthe via holes (see FIG. 7A), therefore, the component body 21 isinhibited from being damaged and breakage of the electronic component 20is thus avoided.

In the electronic component that is used in the conventionalcomponent-embedded substrate, as illustrated in FIG. 1, the externalelectrodes 12 a, 12 b are formed of the conductive paste. In case whereedge parts (parts having small film thicknesses) of the externalelectrodes 12 a, 12 b are irradiated with the laser because of thepositional deviations, the component body 11 may be damaged so thatbreakage of the electronic component 10 may be caused.

In order to avoid such a trouble, it is conceivable to increase the filmthicknesses of the external electrodes 12 a, 12 b as illustrated in FIG.10. A height of the component body 11 has to be decreased in order toincrease the film thicknesses of the external electrodes 12 a, 12 bbecause a height of the electronic component 10 is restricted by athickness of a core substrate. Decrease in the height of the componentbody 11, however, may make it impossible to ensure desiredcharacteristics (capacity value, withstand voltage, or the like, forinstance).

The electronic component 20 according to the embodiment is connected tothe interconnections through the metal plate electrodes 23 a, 23 b andtherefore allows the height of the component body 21 to be made greaterthan the electronic component 10 illustrated in FIG. 10. Accordingly,the electronic component 20 has an advantage in that relaxed restrictionon the size of the component body 21 facilitates ensuring the desiredcharacteristics (capacity value, withstand voltage, or the like, forinstance).

Though the example in which the electronic components to be embedded inthe substrate are capacitors has been described as the embodiment, thedisclosed technique may be applied to resistors, ferrite beads, or otherelectronic components.

(Modification 1)

FIG. 11A is a schematic diagram illustrating an electronic componentaccording to modification 1 of the embodiment and FIG. 11B is aschematic sectional view illustrating a component-embedded substrate inwhich the electronic component according to modification 1 is used.Elements in FIGS. 11A and 11B that are the same as the elements in FIGS.2 and 8 are provided with reference characters that are the same as thereference characters in FIGS. 2 and 8.

In the electronic component 41 illustrated in FIG. 11A, the top andbottom surfaces of the component body 21 are the electrode jointsurfaces and metal plate electrodes 26 a, 26 b are connected to theelectrode joint surfaces through the baked electrodes 22. Sizes of themetal plate electrodes 26 a, 26 b are set so as to exceed sizes of theelectrode joint surfaces of the component body 21.

As illustrated in FIG. 11B, the electronic components 41 are placed inholes formed in the core substrate 31 and are connected to theinterconnections 38 through the vias 37 on a top side and a bottom sideof the component body 21.

(Modification 2)

FIG. 12A is a schematic diagram illustrating an electronic componentaccording to modification 2 of the embodiment and FIG. 12B is aschematic sectional view illustrating a component-embedded substrate inwhich the electronic component according to modification 2 is used.Elements in FIGS. 12A and 12B that are the same as the elements in FIGS.2 and 8 are provided with reference characters that are the same as thereference characters in FIGS. 2 and 8.

In the electronic component 42 illustrated in FIG. 12A, side surfaces ofthe component body 21 are the electrode joint surfaces and metal plateelectrodes 27 a, 27 b in shape of a letter L are connected to theelectrode joint surfaces through the baked electrodes 22.

Sizes of the metal plate electrodes 27 a, 27 b are set so as to exceedsizes of the electrode joint surfaces of the component body 21 and partsof the metal plate electrodes 27 a, 27 b that further extend from bentparts thereof extend sideward from the component body 21.

As illustrated in FIG. 12B, the electronic component 42 is placed in ahole provided in the core substrate 31 and the metal plate electrodes 27a, 27 b are connected to the vias 37 above the core substrate 31.

(Modification 3)

FIG. 13A is a schematic diagram illustrating an electronic componentaccording to modification 3 of the embodiment and FIG. 13B is aschematic sectional view illustrating a component-embedded substrate inwhich the electronic component according to modification 3 is used.Elements in FIGS. 13A and 13B that are the same as the elements in FIGS.2 and 8 are provided with reference characters that are the same as thereference characters in FIGS. 2 and 8.

In the electronic component 43 illustrated in FIG. 13A as well, the sidesurfaces of the component body 21 are the electrode joint surfaces andmetal plate electrodes 28 a, 28 b in shape of a letter L are connectedto the electrode joint surfaces through the baked electrodes 22.

Sizes of the metal plate electrodes 28 a, 28 b are set so as to exceedthe sizes of the electrode joint surfaces of the component body 21. Apart of the metal plate electrode 28 a that further extends from a bentpart thereof is placed on top of the component body 21 and a part of themetal plate electrode 28 b that further extends from a bent part thereofis placed under bottom of the component body 21.

As illustrated in FIG. 13B, the electronic component 43 is placed in ahole provided in the core substrate 31. The metal plate electrode 28 ais connected to the via 37 formed on the top side of the core substrate31 and the metal plate electrodes 28 b is connected to the vias 37formed on the bottom side of the core substrate 31.

(Modification 4)

FIG. 14A is a schematic diagram illustrating an electronic componentaccording to modification 4 of the embodiment and FIG. 14B is aschematic sectional view illustrating a component-embedded substrate inwhich the electronic component according to modification 4 is used.Elements in FIGS. 14A and 14B that are the same as the elements in FIGS.2 and 8 are provided with reference characters that are the same as thereference characters in FIGS. 2 and 8.

In the electronic component 44 illustrated in FIG. 14A as well, the sidesurfaces of the component body 21 are the electrode joint surfaces andmetal plate electrodes 29 a, 29 b are connected to the electrode jointsurfaces through the baked electrodes 22.

In both of the metal plate electrodes 29 a, 29 b, one end part is placedon top of the component body 21 and the other end part is placed underbottom of the component body 21. Sizes of the metal plate electrodes 29a, 29 b are set so as to exceed the sizes of the electrode jointsurfaces of the component body 21.

As illustrated in FIG. 14B, the electronic component 44 is placed in ahole provided in the core substrate 31. In FIG. 14B, the metal plateelectrode 29 a is connected to the via 37 formed on the top side of thecore substrate 31 and the metal plate electrode 29 b is connected to thevias 37 formed on the bottom side of the core substrate 31. Both of themetal plate electrodes 29 a, 29 b may be connected to either of the via37 on the top side of the core substrate 31 and the vias 37 on thebottom side of the core substrate 31.

(Electronic Equipment)

FIG. 15 is a perspective view illustrating an example of electronicequipment that includes the component-embedded substrate 40 (see FIG. 8)described for the embodiment. Though an example in which the electronicequipment is a computer will be described herein, the disclosedtechnique may be applied to electronic equipment other than computer, asa matter of course.

The computer 50 includes the component-embedded substrate 40 on which aCPU 51 is mounted, fans (blowers) 52, a heat pipe 53, hard disk drives(storage devices) 54, and a power unit 55. The component-embeddedsubstrate 40, the fans 52, the heat pipe 53, the hard disk drives 54,and the power unit 55 are housed in a chassis 56.

The electronic equipment (computer 50) according to the embodiment isequipped with the component-embedded substrate 40 having structuresdescribed above, therefore attains high component packaging density, andfacilitates miniaturization of and performance improvement in theelectronic equipment.

All examples and conditional language recited herein are intended forpedagogical purposes to aid the reader in understanding the inventionand the concepts contributed by the inventor to furthering the art, andare to be construed as being without limitation to such specificallyrecited examples and conditions, nor does the organization of suchexamples in the specification relate to a showing of the superiority andinferiority of the invention. Although the embodiment of the presentinvention has been described in detail, it should be understood that thevarious changes, substitutions, and alterations could be made heretowithout departing from the spirit and scope of the invention.

What is claimed is:
 1. An electronic component comprising: a componentbody into which elements are built; and a metal plate electrode that isjoined to the component body by conductive paste so as to beelectrically coupled to the elements, wherein the metal plate electrodeexceeds in size a surface of the component body onto which theconductive paste is deposited.
 2. The electronic component according toclaim 1, wherein the metal plate electrode is joined onto at least asurface on one side of the component body.
 3. The electronic componentaccording to claim 1, wherein a recessed part is formed in a part of themetal plate electrode that faces the component body.
 4. The electroniccomponent according to claim 1, wherein the metal plate electrode isbent so as to have a shape of a letter L.
 5. The electronic componentaccording to claim 1, wherein a part of the metal plate electrode thatprotrudes from the surface onto which the conductive paste is depositedis bent so as to extend along another surface of the component body. 6.The electronic component according to claim 1, wherein two surfaces ofthe component body are each furnished with the metal plate electrode andonly one of the metal plate electrodes exceeds in size the surface ontowhich the conductive paste is deposited.
 7. A component-embeddedsubstrate comprising: a core substrate; an electronic component that isplaced in a hole formed in the core substrate; and insulating layers,interconnections, and vias that are formed on a top side and a bottomside of the core substrate, wherein the electronic component includes acomponent body into which elements are built, and a metal plateelectrode that is joined to the component body by conductive paste so asto be electrically coupled to the elements, and wherein the metal plateelectrode exceeds in size a surface of the component body onto which theconductive paste is deposited.
 8. A method of manufacturing acomponent-embedded substrate, the method comprising: forming a throughhole in a core substrate; placing an electronic component in the throughhole; and forming an insulating layer, an interconnection, and a via onthe core substrate, wherein the electronic component includes acomponent body into which elements are built and a metal plate electrodemade of a metal plate that is joined to the component body by conductivepaste so as to be electrically coupled to the elements, and the metalplate electrode exceeds in size a surface of the component body ontowhich the conductive paste is deposited.